Ios won't play base64 string inside <video> tag

I have a base64 string that looks like this:data:video/mp4;base64...
with an html tag that looks like this:

<video controls preload="auto">
  <source type="video/mp4" [src]="sanitizer.bypassSecurityTrustUrl(" />

**note: sanitizer is the DOMsanitizer so that angular will trust it.

when I click on the play button within the <video> tag nothing plays, there is nothing playing,
when trying to move the slider around I see in the safari console Unhandled Promise Rejection: AbortError: The operation was aborted. but it doesn’t point to any line of code or anything, so it has to be the video player.

this all works fine in Android but not iOS (what a surprise) any one see anything I’m doing wrong?